1. Field
Example embodiments relate to electrical test apparatuses for semiconductor devices. Also, example embodiments relate to handlers (i.e., test robots) that electrically connect semiconductor devices to testers and automatically perform loading, testing, sorting, and/or unloading operations on the semiconductor devices.
2. Description of Related Art
A handler used for an electrical test of a semiconductor device is a kind of automatic test robot loading a semiconductor device, automatically performing an electrical test by electrically connecting the loaded semiconductor device to a tester, sorting semiconductor devices according to the results of the electrical test, and unloading sorted semiconductor devices to the outside.
Recently, large-capacity and high-speed semiconductor memory devices have been developed. Accordingly, the time it takes to electrically test a completed large capacity and high-speed semiconductor memory device has also increased. Thus, increasing test efficiency during an electrical test process of a semiconductor memory device is very important.
Therefore, a tester and a handler, which are test apparatuses for semiconductor memory devices, are developing with focus on realization of a test apparatus that can increase test efficiency. A means of reducing testing time among these tester and handler developments may be generally found by the following methods.
First, it is possible to reduce testing time by changing a test method and reducing a test program. Second, it is possible to reduce testing time by increasing the number of semiconductor memory devices tested at a time, that is, the number of devices under test (DUTs), such as semiconductor devices during a parallel test. However, it is difficult to increase the number of semiconductor memory devices when the increase is applied to the handler as well as to the tester.
Generally, a handler used for a parallel test of semiconductor devices includes a loading unit loading a plurality of semiconductor devices contained in a tray unit; a soak chamber receiving a test tray from the loading unit and aging the test tray at a predetermined temperature for a predetermined time; a test chamber receiving the test tray from the soak chamber, connecting the received test tray directly to the tester, and performing an electrical test on the semiconductor devices loaded into the test tray; a de-soak chamber aging an electrical test-completed semiconductor device at an atmospheric temperature for a predetermined time; and a sorting/unloading unit sorting the tested semiconductor devices and unloading the sorted semiconductor devices according to the test results obtained in the test chamber.
A conventional handler generally uses an air-cooled temperature controller apparatus in order to maintain a constant inner temperature of a test chamber when an electrical test of a semiconductor device is performed at a high or low temperature.
The conventional handler for the semiconductor device cannot maintain a constant inner temperature of a test chamber when the number of semiconductor devices tested inside the test chamber during a parallel test increases. Also, a temperature difference is generated more or less depending on an inner position of the test chamber. To solve this problem, a variety of methods have been proposed to control temperature by controlling an air circulation fan's position and direction, an amount of airflow of a fan, heat generation from a heater, and change of a temperature sensor's position.
However, as high-speed semiconductor devices develop, more heat is generated from the semiconductor devices themselves during an electrical test. Also, as the number of semiconductor devices tested at a time exceeds 256, the whole heat generated in a test chamber increases. Accordingly, temperature control using the conventional methods has reached its limits, and there is a need for new means of temperature control.